Most if not all elevators have a hoistway area, commonly referred to as a pit, which extends some distance below the lowest landing served by an elevator. Such elevator pits commonly have a depth from three to seven feet or more. Access to the floor of the elevator pit is often required for inspection, maintenance and cleaning Most elevator pits do not have an access door as they are located below the grade of the structure. Traditionally, access to an elevator pit is accomplished through the elevator entrance at the lowest landing. With the elevator doors opened and the car moved out of the way, the technician climbs down a fixed and stationary ladder to the pit floor.
In some jurisdictions, applicable codes allow for an elevator pit ladder to have a reduced centerline of rung-to-wall or obstacle dimension of as little as 4.5 inches. Other jurisdictions require the centerline of rung-to-wall or obstacle dimension to be the full OSHA mandated 7 inches. On many new and existing elevator installations, there is insufficient clearance between the moving car and the building structure to fit a fixed, stationary ladder with the code-prescribed centerline of rung-to-wall or obstacle dimension.
Thus, the need exists for a retractable elevator pit ladder that can provide the code minimum centerline of rung-to-wall or obstacle dimension yet provide the necessary clearance to the operating elevator car.